The most representative background art relating to this invention is the U.S. Pat. No. 2,762,176 issued Sept. 11, 1956 to K. D. Knapp et al. for a wrapping machine. However, this type of machine does not form a package in a continuous web and fill it with a product before cutting the package from the web. It does not therefore solve the problems presented by a complete automated product packaging machine that need fold and seal a web to form a package about a product with enough versatility to handle packages of various sizes with various kinds of products inserted therein.
Automatic multi-purpose packaging machines are generally known such as in U.S. Pat. No. 3,054,246 issued Sept. 18, 1962 to J. H. Stroop.
The mechanisms involved tend to be complex and critical as to changes in package contents and size. Packaging systems currently commercially available such as the form-fill-seal system of Sigma Systems, Inc., of 231 Westhampton Ave., Capitol Heights, Maryland 20027, and of Package Machinery Co., East Longmeadow, Maine, are complex, expensive and present difficulties in replacing loading and threading web rolls. Most systems require passing the web over a large number of rollers in a web feed system to equalize forces along the web while withstanding the longitudinal forces exerted along the web without excessive stretching or tearing, and to permit registration and alignment of the web throughout the system and particularly at work stations. Thus, web roll changeover and threading through these complex systems is time consuming and tedious. The cabinet structure and location of the web path also in prior art machines interferes with web change although readily accessible and changeable web rolls are known in less complex systems such as in U.S. Pat. No. 3,988,970 issued Nov. 2, 1976 to V. Hansen et al.
In some machines an intermittent asynchronous cycle is used. This puts great demands on web tension and webs frequently stretch or break when processing speeds are increased with highly accelerated starts or yanks on the web for pulling enough tape from a storage roll to form each package. Wherever reciprocating mechanisms are used to process these problems increase because of start up acceleration forces.
Another problem is that the web travel need be interrupted by a relatively long package seal time that is difficult to achieve consistently with high output capacity because it is necessary to keep the web stationary while sealing. This reduces output speed and requires complex web feeding systems to relieve strains and to produce timing of the required events in an automated system.
Timing and control systems are therefore very complex in fully automated packaging machines.
A general object of this invention therefore is to resolve one or more of these prior art problems in a novel packaging system with simplified web feed and controls.
It is another object of this invention to provide in a versatile package forming machine a simplified web processing system useful in a versatile packaging operation that can run asynchronously at high packaging speeds and process different package sizes automatically.
Also it is an object of this invention to provide a web feed system simplified with few parts and having all parts readily accessible for quick replacement of a new web roll.
Other objects, features and advantages of the invention will be found throughout the drawings and description of the invention and its preferred embodiment.